You know the thing with acropora ain't hard to explain in my opinion. Cooper is acting as a poison when it comes to corals (I know it is used in Zeovit etc.). In a smaller amount it just bleeches acros. But just a small amount on top and you can kiss them goodbye.
So all the trace elements are not the reason in my opinion. Sure they will keep your acros from growing and maybe do something with their colors, but most certainly not kill them.
PO4 is a bit higher, but same thing as with trace elements, that stuff won't kill your acros.
As for the Triton methode, for me its a no brainer. You can exactly controll what you put in your tank and thus develope it in the direction you want it to be.